The field of the invention is collapsible furniture.
Folding chairs are relatively popular, because they can be stored with considerably reduced space requirements when compared to non-folding chairs. Nevertheless, folding chairs still require relatively large space, since the dimension of the folding chair is generally reduced only along one space coordinate (e.g., reduced length). To further reduce the space requirement, collapsible chairs have been developed, in which further size reduction is achieved by folding the chair along at least two space coordinates (e.g., length and width). Various collapsing chairs are known in the art.
For example, Cook et al. describes in U.S. Pat. No. 5,921,621 a collapsible chair with a foldable back rest, in which the chair has four legs that support the corners of a flexible square seat. The legs are movably attached to each other at about their respective midpoints, and the seat is collapsed in width and depth by turning the legs around the midpoint. While Cooks chair is relatively easy to unfold and collapse, Cooks chair provides relatively little stability and is prone to tipping over.
Improved stability can be achieved by including slidable cross bars between the legs as described in U.S. Pat. No. 6,082,813 to Chen and U.S. Pat. No. 5,984,406 to Lee. Chen""s chair advantageously collapses to a relatively compact form. However, the position of the back support is limited to a vertical position, which may not be comfortable over a prolonged period. On the other hand, Lee""s chair provides an angled back rest, although it lacks a seat support entirely.
In addition to the problems of the collapsible chairs mentioned above, all or almost all of the known collapsible chairs suffer from a common disadvantage in that the seat will loose tension once the seat supports the weight of a person. Moreover, where known chairs are collapsible in a single motion, such chairs do typically fail to provide a seat support rod onto which the seat can be tensioned. Alternatively, where known chairs have a pair of seat support rods, such chairs generally require at least two folding motions (e.g., one motion in which the seat is folded upwards followed by one motion in which the seat is folded in a side-to-side movement). Therefore, there is a need to provide improved methods and apparatus for collapsible chairs.
The present invention is directed to collapsible chairs, and in particular to collapsible chairs that can be collapsed in a single movement.
In one aspect of the inventive subject matter, a collapsible chair has a front leg, a rear leg, a cross brace, a seat support rod, and a back rest, wherein the seat support rod is rotatably coupled to the front leg, and wherein the back rest is coupled to the front leg, and wherein the cross brace and the seat support rod are rotatably and slidably coupled to the rear leg in a manner such that the chair collapses in a single movement. Especially preferred modes of rotatably and slidably coupling of the cross brace and the seat support rod include a slidable connector that is slidably coupled to the rear leg and that further includes a first rotatable coupling to one end of the cross brace and a second rotatable coupling to one end of the seat support rod.
Contemplated chairs may further include a second front leg, in which the chair collapses in a single movement such that the front legs approximate each other when the seat support rod pivots towards the front leg. Alternatively or additionally, suitable configurations may further comprise a second seat support rod and a second cross brace, wherein the second cross brace is rotatably coupled to the front leg and rotatably coupled to the second seat support rod. It is generally contemplated that a seat is coupled to the seat support rod, wherein in especially preferred chairs the seat is contiguous with the back rest.
Thus, in another aspect of the inventive subject matter, a collapsible chair may have a pair of front legs, a pair of rear legs, a first pair of cross braces, a second pair of cross braces, and a pair of seat support rods. In such chairs, a seat may be coupled to the pair of seat support rods, and a back rest may be coupled to the front legs, wherein the seat is contiguous with the back rest, wherein one cross brace of the first pair of cross braces is rotatably coupled to one of the front legs, and rotatably and slidably coupled to one of the rear legs, and wherein the other of the first pair of cross braces is rotatably coupled to the other of the front legs, and rotatably and slidably coupled to the other of the rear legs. Furthermore, it is contemplated that in such chairs one cross brace of the second pair of cross braces is rotatably coupled to the one of the front legs, and rotatably coupled to one of the seat support rods, and the other of the second pair of cross braces is rotatably coupled to the other of the front legs and rotatably coupled to the other of the seat support rods.
In still further contemplated aspects of the inventive subject matter, a collapsible furniture includes a connector that is slidably coupled to a leg and that further includes a first rotatable coupling to one end of a cross brace and a second rotatable coupling to one end of a seat support rod. In particularly preferred connectors, the first rotatable coupling allows rotation of the cross brace in at least x-coordinate and y-coordinate. Alternatively or additionally, the connector may be separable into two portions, wherein the first portion comprises the first rotatable coupling and wherein the second portion comprises the second rotatable coupling.
Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.